Introduction sets for surgical procedures including such procedures as (1) placing a cannula adjacent a cavity to be drained, (2) introducing a diagnostic tool, and (3) introducing surgical tools, such as a biopsy probe, a trephine, or other cutting probe, are well known in the art. These introduction sets generally include a straight trocar with a sharpened end. The trocar, being generally a small diameter rigid wire, can be inserted into the subject and located adjacent the desired site. By insertion over the trocar, a combination of a dilator and a cannula can be introduced through the subject to the desired site. The cannula includes generally a straight tubular body with the dilator including a second straight tubular body which is inserted inside the tubular body of the cannula. The dilator includes a conical end which extends from the tubular body of the cannula. As the cannula and dilator pass over the trocar, the dilator expands the tissue of the subject to accommodate the larger diameter tubular body of the cannula. Once the cannula has been properly inserted, the trocar can be extracted along with the dilator in order to allow the desired procedure to be performed through the unobstructed cannula.
At times, due to the location of the desired site to be accessed in the subject, it is difficult to use a straight cannula. Thus there is a requirement for an introduction set which can accomplish other than a straight-in approach to the desired site.